'Man,' W.B. Yeats famously claimed, 'has created death'. This is manifestly untrue: evolutionary theory tells us that man was created out of death. H. sapiens grew out of a rising pyramid of the unsurviving unfit. What Yeats really meant was that Man, uniquely, has made death explicit. In us, transience, the condition of all things, has been transformed into a tragic mystery black-edged with terror. And so we have invented immortality, to cancel the certainty of physical death with the promise of eternal life. Unfortunately, the idea of immortality may itself be proving mortal.

At first, eternal life was located in a hidden world, removed from space and time, from here and there, to be revealed after death had disrobed us of our perishable flesh. In this place, ancestors were joined, friends reunited, God met face-to-face, and the true meaning of everything disclosed to our awestruck gaze. Most importantly, change was arrested. And therein lay the catch: unchanging reality could just as well be unremittingly horrible as permanently pleasant. This uncertainty, which haunted humans whenever they thought of death, was exploited by those who wished to command their obedience. The 'Hereafter' became, in the hands of those who were accredited with a privileged understanding of the will of God, an instrument to terrorise the lower orders. Mesmerised by promises of eternal bliss and threats of unending punishment, men and women stayed in line and colluded in their own continuing subjection.

That, at least, ...